To get started, we need to organize as much of the given information as possible into a known formula. Since the volume (750p cm3) and height (30 cm) of the cylinder are given, we will start with the equation for volume.

This type of word problem involves the use of known formulas. Usually we used one of the formulas for either volume or surface area, depending on what information was given, to solve for the radius or height of the cylinder. In one case, when the height and surface area are given, we were required to solve a quadratic equation for the value of r. If that expression had not factored easily, we would have had to used the quadratic formula.

Once values of both r and h were known, the volume and surface area formulas were used. These problems require careful arithmetic since it is often difficult to determine whether or not our answers are reasonable. Notice that the surface area formula can be written in more than one way. Using more than one of these can serve as a way to check answers or make a calculation easier.